1. Field of the Invention
The invention relates generally to a seal assembly capable of sealing a through-wall shaft in both static and rotary modes and particularly relates to such a seal assembly which can be rapidly assembled and disassembled without the use of tools to allow cleaning.
2. Description of the Prior Art
The prior art is replete with seal structure capable of sealing a through-wall rotary shaft. Such prior seal structure takes a wide variety of forms which in most applications do not require the ability to disassemble the seal without the use of tools so that the seal structure can be subjected to cleaning on a regular basis. In the food processing arts, structure contacting foodstuffs during processing must be cleaned daily in order to meet sanitation standards. Where at all possible, food processing structure must be capable of disassembly without the use of special tools. Further, it is necessary from a practical standpoint to cause such food processing structure to be easily and rapidly assembled and disassembled so that daily cleaning of such structure does not become an onorus burden with the attendant possibility that cleaning of the structure will be haphazardly attended to.
The particular background of the present invention relates to cooking kettles having agitator structure rotatable therewithin to process food materials which are heated or cooked within the kettle. An example of such a kettle and agitator assembly is provided in U.S. Pat. No. 4,571,091 to Pardo et al. Numerous other examples of kettle/agitator arrangements exist in the art, these structures generally being provided with a rotary shaft which extends through a wall of the kettle, it being necessary to seal the kettle at the opening through which the shaft of the agitator extends. In this use environment, and especially with kettles of a size of approximately 80 gallons or more, it is difficult for an operator to gain ready access to the interior of a kettle for removal of sealing structure disposed primarily within the interior of the kettle such that said sealing structure must be removed with access to the interior of the kettle. In such situations, it is virtually a necessity to provide sealing structure exteriorly of the kettle and which can be disassembled, preferably without the use of tools, in a rapid and ready fashion such that the sealing structure can be easily cleaned.
Prior patents which disclose structure useful in the sealing of a rotary shaft include U.S. Pat. No. 2,635,931 to May who provides an "O"-ring seal capable of sealing a rotary joint in a rotary mode. Steidel, in U.S. Pat. No. 3,382,015, describes a bearing which has some sealing capability, the bearing using a spring clip and holder to retain a bearing in position. In U.S. Pat. No. 3,584,923, Goossens describes a bearing device including a slotted end plate, slotted bearing and spring-like wedge which, while primarily serving as a bearing, provides some sealing function. Dubay, in U.S. Pat. No. 3,751,122, discloses a bushing for a sanitary conveyor, which bushing accepts and at least partially seals a shaft. Wilczewski, in U.S. Pat. No. 4,502,796, discloses a bearing for a rotary shaft, the bearing being sectional in nature and having a retaining clip positioned to release bearing sections on removal of the clip.
The prior art noted above generally discloses "O"-ring seals associated with bearing-like elements and wherein at least some of the structures are held together by C-shaped clips and similar structure to allow disassembly of the bearing structures.
As evidenced by the foregoing patents and that prior art known to the applicant, the prior art does not envision a sanitary sealing assembly capable of sealing a rotary shaft in both static and rotary modes and which can be rapidly and readily assembled and disassembled to allow cleaning according to sanitation standards and preferably without the use of tools. Further, the present invention provides relatively simple and inexpensive structure capable of being mounted directly to external surfaces of a cooking kettle or similar structure having a wall through which a rotary shaft extends, the present sealing assembly acting to efficiently seal the shaft yet be readily removable within a very short period of time and with a minimum of physical effort.